JPH10186661A - Chemical sensitizable negative resist composition and negative resist pattern forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resist compsn. having high sensitivity and high resolution, excellent in heat resistance and capable of forming a resist pattern excellent in profile shape and to provide a negative resist pattern forming method. SOLUTION: This resist compsn. contains an alkali-soluble resin, a compd. generating an acid when being irradiated and compd. causing crosslinking reaction in the presence of the acid. The alkali-soluble resin is a copolymer having at least constituent units of hydroxystyrene of a mixture of the copolymer with a hydroxystyrene homopolymer. The wt. average mol.wt. of the copolymer is 2,000-4,000 and the ratio of the wt. average mol.wt. of the copolymer to the number average mol.wt. is 1.0-2.0. The alkali-soluble resin dissolves in 2.38wt.% aq. soln. of tetramethylammonium hydroxide at 23 deg.C at 50-300nm/sec velocity.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemically amplified negative resist composition, and more particularly, it has high sensitivity, high resolution, can be patterned at various thicknesses, has excellent heat resistance, and has excellent profile. The present invention relates to a chemically amplified negative resist composition capable of forming a resist pattern having an excellent shape, and a method for forming a negative resist pattern using the chemically amplified negative resist composition.

[0002]

2. Description of the Related Art In recent years, in the production of electronic components such as semiconductor devices and liquid crystal display devices, finer processing has been advanced, and resists having high resolution and sensitivity, and formation of resist patterns having good profile shapes have been developed for resists to be used. It has come to be required. As such a resist, a chemically amplified resist that causes a reaction that changes the solubility in a developing solution by the catalytic action of an acid generated by irradiation with radiation has attracted attention, and many chemically amplified negative resist compositions have been proposed. Photolithography is used for the production of electronic components using the chemically amplified negative resist composition.In this photolithography, the chemically amplified negative resist composition is applied on a substrate such as a silicon wafer. After applying the resist, irradiating it with radiation through a mask pattern and developing it to form a resist pattern, etching is performed using the resist pattern as a protective film. However, the radiation used in the photolithography is ultraviolet,
There has been a trend toward shorter wavelengths of excimer laser light such as pUV, KrF, and ArF, and furthermore, the use of electron beams and X-rays has been studied in earnest. In order to form a good resist pattern in response to the short-wavelength radiation, it is important that each component constituting the chemically amplified negative resist composition has low absorption of the radiation, and a novolak-based resin conventionally used Therefore, polyvinyl phenol-based polymers having low radiation absorption cannot be used as a resin component for the above-mentioned applications because of their large absorption of radiation. A chemically amplified negative resist composition containing such a polyvinylphenol-based polymer as a resin component is disclosed in
293339, JP-A-2-15270, JP-A-4-163552, JP-A-6-67433, JP-A-7-31463, and the like. Negative-acting resist compositions also suffered from poor resolution. Thus, as a chemically amplified negative resist composition for improving the above, a 4-hydroxystyrene-styrene copolymer is used as the alkali-soluble resin, the styrene content is 5 to 20% in molar ratio, and the weight average molecular weight is 6000 to 25000. A chemically amplified negative resist composition described above has been proposed in Japanese Patent Application Laid-Open No. 7-238196.

[0003]

However, when a resist pattern is formed using the chemically amplified negative resist composition described in the above publication, there is a problem that the contrast is inferior. In addition, in any of the chemically amplified negative resist compositions described in the above publications, when the film thickness of the resist is 2.0 μm or more, particularly 3.0 μm or more, a so-called microbridge phenomenon occurs in which the resist patterns are bridged with each other. Or, there is a drawback such as the occurrence of roundness on the upper part of the pattern.

In view of this situation, the present inventors have conducted intensive studies and as a result, have found that the resin component of the chemically amplified negative resist composition is dissolved in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23 ° C. Assuming that the resin component has a speed in a sub-specific range, ultraviolet rays, deep U
It has high sensitivity and high resolution to excimer laser light such as V, KrF and ArF, electron beam, can be patterned with various film thicknesses, and has excellent heat resistance and a resist pattern with excellent profile shape. It has been found that a chemically amplified negative resist composition that can be formed is obtained, and the present invention has been completed. Ie

The present invention provides a chemically amplified negative resist composition capable of forming a resist pattern having high sensitivity to radiation, high resolution, excellent heat resistance, and excellent profile shape, even at various film thicknesses. The purpose is to provide.

Another object of the present invention is to provide a method for forming a negative resist pattern using the above chemically amplified negative resist composition.

[0007]

The present invention, which achieves the above object, comprises a crosslinking reaction in the presence of (A) an alkali-soluble resin, (B) a compound capable of generating an acid upon irradiation with radiation, and (C) an acid. in the chemically amplified negative resist composition containing a compound of the component (a), and (b) at least hydroxystyrene constituent unit, the weight average molecular weight (M _W) is 2000 to 4000, a weight average molecular weight the number average molecular weight (M _N) and a ratio of (M _W / M _N) is 1.0 to 2.
0 or 2.38% by weight of the component (A) at 23 ° C. of 2.38% by weight of tetramethylammonium, which is a copolymer alone or a mixture of the component (A) and the hydroxystyrene homopolymer. The present invention relates to a chemically amplified negative resist composition having a dissolution rate in an aqueous hydroxide solution in the range of 50 to 300 nm / s, and a method for forming a negative resist pattern using the same.

As described above, the component (A) is constituted (A)
The component is a copolymer having at least a hydroxystyrene structural unit, and the copolymer is hydroxystyrene,
It comprises a hydroxystyrene structural unit such as α-alkylhydroxystyrene and a structural unit other than the hydroxystyrene structural unit. Preferred as a monomer forming a structural unit other than the hydroxystyrene structural unit,
Examples thereof include a monomer in which the hydroxyl group of hydroxystyrene is substituted with another group or a monomer having an α, β-unsaturated double bond. As the other group that substitutes the hydroxyl group of the hydroxystyrene, an alkali dissolution inhibiting group that is not dissociated by an acid is used. Examples of the alkali dissolution inhibiting group include a substituted or unsubstituted benzenesulfonyloxy group, a substituted or unsubstituted naphthalene sulfonyloxy group, a substituted or unsubstituted benzenecarbonyloxy group, and a substituted or unsubstituted naphthalenecarbonyloxy group. Specific examples of the substituted or unsubstituted benzenesulfonyloxy group include a benzenesulfonyloxy group, a chlorobenzenesulfonyloxy group, a methylbenzenesulfonyloxy group, an ethylbenzenesulfonyloxy group, a propylbenzenesulfonyloxy group, a methoxybenzenesulfonyloxy group, An ethoxybenzenesulfonyloxy group, a propoxybenzenesulfonyloxy group, an acetaminobenzenesulfonyloxy group and the like, and specific examples of a substituted or unsubstituted naphthalenesulfonyloxy group As naphthalenesulfonyloxy group, chloronaphthalenesulfonyloxy group, methylnaphthalenesulfonyloxy group, ethylnaphthalenesulfonyloxy group, propylnaphthalenesulfonyloxy group, methoxynaphthalenesulfonyloxy group, ethoxynaphthalenesulfonyloxy group, propoxynaphthalenesulfonyloxy group, acetoacetate An aminonaphthalenesulfonyloxy group is preferred. Further, examples of the substituted or unsubstituted benzenecarbonyloxy group and the substituted or unsubstituted naphthalenecarbonyloxy group include those in which the above-mentioned substituted or unsubstituted sulfonyloxy group is replaced with a carbonyloxy group. Among them, an acetaminobenzenesulfonyloxy group or an acetaminonaphthalenesulfonyloxy group is preferable.

Specific examples of the monomer having an α, β-unsaturated double bond include styrene, chlorostyrene,
Styrene monomers such as chloromethylstyrene, vinyltoluene and α-methylstyrene; acrylic monomers such as methyl acrylate, methyl methacrylate and phenyl methacrylate; vinyl acetate monomers such as vinyl acetate and vinyl benzoate. However, among them, styrene is preferred. For example, poly (4-hydroxystyrene-styrene), poly (4-hydroxystyrene-methylstyrene) copolymer obtained from hydroxystyrene and styrene is preferable because it has high resolution and high heat resistance.

The above component (a) has a weight average molecular weight of 200
0 to 4000, preferably 2300 to 3000, and the ratio of the number average molecular weight (M _N ) to the weight average molecular weight (M _w ) (hereinafter referred to as molecular weight distribution) is 1.0 to 2.0, preferably 1.1 to 1 .5 is good. Weight average molecular weight of 20
When it is less than 00, there are difficulties in developing characteristics, heat resistance and the like, and when the weight average molecular weight exceeds 4,000, resolution is remarkably reduced. Further, when the molecular weight distribution exceeds 2.0, the patterning becomes unstable, the cross-linking speed and the degree of cross-linking vary, and uneven development tends to occur.

The component (A) which constitutes the component (A) by mixing with the component (A) includes hydroxystyrene such as p-hydroxystyrene, α-methylhydroxystyrene,
Examples include a radical polymer or an ionic polymer of an α-alkylhydroxystyrene monomer such as α-ethylhydroxystyrene, and poly (p-hydroxystyrene) is particularly preferable. The component (b) should have a weight average molecular weight in the range of 2,000 to 4,000 and a molecular weight distribution in the range of 1.0 to 2.0 in order to balance the crosslinking speed and the degree of crosslinking, and to prevent uneven development. Good.

The above component (a) has a dissolution rate of 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23 ° C. of 50 to 200 nm / s, preferably 60 to 150 nm / s, and more preferably 80 to 200 nm / s.
あ る 100 nm / s is required. If the dissolution rate is less than 50 nm / s, the contrast is significantly reduced, and if the dissolution rate is more than 200 nm / s, the thickness of the photocured portion is reduced, which is not preferable. The dissolution rate of a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23 ° C. (hereinafter referred to as “dissolution rate”) refers to a method in which an alkali-soluble resin is dissolved in a solvent, and a film thickness of about 1.0 μm is formed on a silicon wafer. And heated at 110 ° C. for 90 seconds, and then immersed in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23 ° C. and refers to the amount of film reduction (nm) per unit time (second).

The dissolution rate of the component (A) is 50 to 200 nm.
In order to adjust to / s, the hydroxystyrene structural unit of the component (a) and the structural unit other than the hydroxystyrene structural unit are in a molar ratio of 80:20 to 90:10, preferably 80:
The ratio is preferably in the range of 20 to 85:15, or the component (a) and the component (b) are preferably mixed. However, when adjusting the dissolution rate to 200 to 300 nm / s, it is necessary to mix the components (a) and (b). In particular, when a resist pattern having a thickness of 3.0 μm or more is formed, a mixed system in which the component (b) is mixed is preferable because a chemically amplified negative resist composition having excellent sensitivity and shape characteristics can be prepared. . When a resist pattern having a thickness of 3.0 μm or more is formed, the dissolution rate of component (A) obtained by mixing component (a) and component (b) is 50 to 50 μm.
300 nm / s, preferably 150 to 280 nm / s,
It is more preferable that the mixing ratio is adjusted to 200 to 250 nm / s, and the mixing ratio of the component (a) and the component (b) is 2: 1 to 1: 2 by weight, preferably about 1: 1. It is preferable to mix in the range of 1.

The component (B) of the present invention is not particularly limited, but specifically, (a) bis (p-toluenesulfonyl) diazomethane, bis (1,1-dimethylethylsulfonyl) diazomethane, bis (cyclohexyl) Bissulfonyldiazomethanes such as sulfonyl) diazomethane and bis (2,4-dimethylphenylsulfonyl) diazomethane; (b) 2-nitrobenzyl p-toluenesulfonate, 2,6-dinitrobenzyl p-toluenesulfonate, p-tri Fluoromethylbenzenesulfonic acid 2,4
Nitrobenzyl derivatives such as dinitrobenzyl;
(C) pyrogallol aliphatic or aromatic sulfonic esters such as pyrogallol methanesulfonic acid ester (pyrogallol trimesylate), pyrogallol benzenesulfonic acid ester, and pyrogallol p-toluenesulfonic acid ester; (d) Chemical formula 8 And sulfonic acid esters of N-hydroxyimide compounds such as

[0015]

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[0016]

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[0017]

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[0018]

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(E) 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5
-Triazine, 2- (4-methoxynaphthyl) -4,6
-Bis (trichloromethyl) -1,3,5-triazine, 2- [2- (2-furyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5-triazine,
-[2- (5-methyl-2-furyl) ethenyl] -4,
6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (3,5-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -1,3,5
-Triazine, 2- [2- (3,4-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl)-
1,3,5-triazine, 2- (3,4-methylenedioxyphenyl) -4,6-bis (trichloromethyl)-
1,3,5-triazine, tris (1,3-dibromopropyl) -1,3,5-triazine, tris (2,3-
Halogen-containing triazine compounds such as dibromopropyl) -1,3,5-triazine; (f) general formula 12

[0020]

Embedded image (Wherein, R ¹⁴ represents a monovalent to trivalent organic group, R ¹⁵ represents a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic compound group, and n represents 1 to 3 Which is a natural number.)

[0021]

Embedded image (Wherein, R ¹⁶ and R ¹⁷ are each a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group, or aromatic compound group, and R ¹⁶ and R ¹⁷ are simultaneously an aromatic compound group. And a compound represented by the general formula

[0022]

Embedded image (Wherein, R ¹⁸ is a divalent organic group, and R ¹⁹ is a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic compound group). Here, the aromatic compound group refers to a group of a compound exhibiting physical and chemical properties unique to an aromatic compound, such as a phenyl group,
Examples include an aromatic hydrocarbon group such as a naphthyl group and a heterocyclic group such as a furyl group and a thienyl group. These may have one or more suitable substituents on the ring, for example, a halogen atom, an alkyl group, an alkoxy group, a nitro group and the like. R ¹⁹ is particularly preferably an alkyl group having 1 to 4 carbon atoms,
Examples include a methyl group, an ethyl group, a propyl group, and a butyl group. Further, (g) general formula 15

[0023]

Embedded image (Wherein, R ^{20 to} R ²² may be the same or different and each represents a halogenated alkyl group); (h) bis (p-tert-butylphenyl) iodonium trifluoromethane Onium salt-based acid generators such as sulfonate and triphenylsulfonium trifluoromethanesulfonate; and (i) benzointresheet-based acid generators can also be used. The acid generators may be used alone or in combination of two or more.
Among the acid generators, the acid generator represented by the general formula 12 has a low sublimation property, and does not sublime from the film in the drying step or the heating step of the film and contaminate the inner wall of the device. Among them, the acid generator represented by the general formula 13 is an i-line (365n
Preferred is an acid generator for m), particularly preferably a compound wherein R ¹⁶ is an aromatic compound group and R ¹⁷ is a lower alkyl group. As the acid generator represented by the above general formula 13, a compound in which R ¹⁶ is any one of a phenyl group, a methylphenyl group, and a methoxyphenyl group and R ¹⁷ is a methyl group, specifically, α- (methyl Sulfonyloxyimino) -1-phenylacetonitrile, α- (methylsulfonyloxyimino) -1- (p-methylphenyl) acetonitrile, α
-(Methylsulfonyloxyimino) -1- (p-methoxyphenyl) acetonitrile is preferred. Especially α-
(Methylsulfonyloxyimino) -1-phenylacetonitrile has excellent transparency and is preferable for a thick film having a thickness of 3.0 to 6.0 μm. As the acid generator represented by the general formula 14, specifically, the following chemical formulas 16 to 23

[0024]

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[0025]

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[0026]

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[0027]

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[0028]

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[0029]

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[0030]

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[0031]

Embedded image And an acid generator represented by the formula: Formula 13 above
Since the acid generator represented by the formula (1) has a strong absorptivity to i-rays, when it is contained in a resist composition for a thick film having a thickness of 3.0 to 6.0 μm, it is used in combination with the acid generator represented by the general formula (14). Is good. In particular, a combination of α- (methylsulfonyloxyimino) -1- (p-methoxyphenyl) acetonitrile and an acid generator represented by Chemical Formula 20 is preferable.

When the chemically amplified negative resist composition of the present invention is used as a resist for an excimer laser, it is preferable to use an acid generator represented by the general formula 15 as the component (B). Particularly, tris (2,3-dibromopropyl) isocyanurate is preferable.

The acid generator is preferably blended in an amount of 0.5 to 30 parts by weight based on 100 parts by weight of the component (A).
If the amount of the acid generator is less than 0.5 part by weight, the effect is insufficient. If the amount exceeds 30 parts by weight, the acid generator cannot be completely dissolved in the solvent and the miscibility with the resin component is poor.

As the compound (C) of the present invention which undergoes a cross-linking reaction in the presence of an acid (hereinafter referred to as a cross-linking agent), a conventionally known cross-linking agent can be used and is not particularly limited. Amino resins having, specifically, methoxymethylated melamine resin, ethoxymethylated melamine resin, propoxymethylated melamine resin, butoxymethylated melamine resin, methoxymethylurea resin,
Nikarac MX-750, Nikarac MX-7 which are commercially available
06, Nikarac MX-101, Nikarac MX-03
2, Nikarac MX-708, Nikarac MX-40,
Nikarac MX-31, Nikarac MS-11, Nikarac MW-22 and Nikarac MW-30 (trade names of alkoxymethylated melamine resin, manufactured by Sanwa Chemical Co., Ltd.), Nikarac MX-290 and Nikarac N-20
09 (the above-mentioned trade names of alkoxymethylated urea resins, manufactured by Sanwa Chemical Co., Ltd.), benzene compounds having an alkoxyl group, phenol compounds having a hydroxyl group or an alkoxyl group, JP-A-4-215668, JP-A-7-306531 Compounds described in gazettes and the like can be mentioned.

The crosslinking agent is preferably blended in an amount of 3 to 70 parts by weight based on 100 parts by weight of the component (A). If the amount of the crosslinking agent is less than 3 parts by weight, the formation of the resist pattern becomes poor, and if it exceeds 70 parts by weight, the developability is reduced.

In addition to the above, the chemically amplified negative resist composition of the present invention preferably contains an organic carboxylic acid or an amine for the purpose of improving the stability over time and the exposure latitude. As the organic carboxylic acids, any of saturated or unsaturated aliphatic carboxylic acids, alicyclic carboxylic acids, oxycarboxylic acids, alkoxycarboxylic acids, ketocarboxylic acids, and aromatic carboxylic acids can be used, and are not particularly limited. For example, monovalent or polyvalent aliphatic carboxylic acids such as formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, 1,1-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4
-Cyclohexanedicarboxylic acid, alicyclic carboxylic acid such as 1,1-cyclohexyldiacetic acid, acrylic acid, crotonic acid, isocrotonic acid, 3-butenoic acid, methacrylic acid,
4-pentenoic acid, propiolic acid, 2-butyric acid, maleic acid, fumaric acid, unsaturated aliphatic carboxylic acids such as acetylene carboxylic acid, oxycarboxylic acids such as oxyacetic acid,
Examples thereof include alkoxycarboxylic acids such as methoxyacetic acid and ethoxyacetic acid, and ketocarboxylic acids such as pyruvic acid. Particularly, alicyclic carboxylic acids, unsaturated aliphatic carboxylic acids, and aromatic carboxylic acids are preferably used.

The aromatic carboxylic acids include, for example, p-hydroxybenzoic acid, o-hydroxybenzoic acid,
-Hydroxy-3-nitrobenzoic acid, 3,5-dinitrobenzoic acid, 2-nitrobenzoic acid, 2,4-dihydroxybenzoic acid, 2,5-dihydroxybenzoic acid, 2,6-dihydroxybenzoic acid, 3,4 -Dihydroxybenzoic acid,
3,5-dihydroxybenzoic acid, 2-vinylbenzoic acid,
SAX commercially available as 4-vinylbenzoic acid, phthalic acid, terephthalic acid, isophthalic acid, and phenolic compounds
(Trade name, manufactured by Mitsui Toatsu Chemicals, Inc.), and in particular, benzoic acid having a substituent at the o-position, for example, o-
Hydroxybenzoic acid, o-nitrobenzoic acid, phthalic acid and the like are preferred.

The above aromatic carboxylic acids may be used alone or in combination of two or more. With the addition of these aromatic carboxylic acids, it is possible to form a resist pattern having a good cross-sectional shape, excellent stability over time after exposure, and a relationship with the length of time until heat treatment performed after exposure. And a good profile shape can be formed.

The compounding amount of the organic carboxylic acids is as follows:
It is used in the range of 0.01 to 3 parts by weight based on 100 parts by weight of the component (A). The compounding amount of organic carboxylic acids is 0.0
If the amount is less than 1 part by weight, the effect of the addition cannot be sufficiently obtained, and if it exceeds 3 parts by weight, the developing property is undesirably reduced.

The amines include aliphatic amines, aromatic amines, and heterocyclic amines. Specific examples of the aliphatic amine include methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, n-propylamine, and di-n.
-Propylamine, tri-n-propylamine, isopropylamine, tripentylamine and the like.
Specific examples of the aromatic amine include benzylamine, aniline, N-methylaniline, N, N-dimethylaniline, o-methylaniline, m-methylaniline,
Examples include p-methylaniline, N, N-diethylaniline, diphenylamine, di-p-tolylamine and the like. Further, specific examples of the heterocyclic amine include pyridine, o-methylpyridine, o-ethylpyridine, 2,3
-Dimethylpyridine, 4-ethyl-2-methylpyridine, 3-ethyl-4-methylpyridine and the like, and particularly strong amines having a low boiling point, such as methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, Aliphatic amines such as triethylamine and tripentylamine are preferred, and among them, triethylamine and tripentylamine are preferred. These may be used alone or in combination of two or more.

The amount of the amines is in the range of 0.01 to 5 parts by weight based on 100 parts by weight of the component (A).

Further, a light absorbing agent is preferably added to the chemically amplified negative resist composition of the present invention. Examples of the light absorbing agent include 1- [1- (4-hydroxyphenyl)
Isopropyl] -4- [1,1-bis (4-hydroxyphenyl) ethyl] benzene, bis (4-hydroxy-
Naphthoquinone, a polyphenol such as 3,5-dimethylphenyl) -3,4-dihydroxyphenylmethane
1,2-diazide-5-sulfonic acid ester, benzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2,3,3 ′, 4,4 ′, 5′-hexahydroxybenzophenone, 4-dimethyl Amino-2 ',
4'-dihydroxybenzophenone, 5-amino-3-
Methyl-1-phenyl-4- (4-hydroxyphenylazo) pyrazole, 4-dimethylamino-4'-hydroxyazobenzene, 4-diethylamino-4'-ethoxyazobenzene, 4-diethylaminoazobenzene, curcumin and the like can be mentioned. By mixing these light absorbing agents, the effect of improving sensitivity and resolution can be achieved, and a rectangular resist pattern can be formed without forming a wavy cross-sectional shape, so that it is preferably used. The light-absorbing agent can be added in an amount of 0.5 to 15 parts by weight based on 100 parts by weight of the component (A). If the compounding amount exceeds 15 parts by weight, the profile shape is deteriorated, which is not preferable. The composition may further contain, if desired, a miscible additive, for example, an additional resin for improving the performance of the resist film, a plasticizer, a stabilizer, a coloring agent, a surfactant, and a coupling agent such as hexamethyldisilazane. Can be added and contained within a range not to impair the performance.

The chemical amplification type negative resist composition of the present invention is preferably used in the form of a solution obtained by dissolving each of the above components in a solvent. Examples of such solvents include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, propylene glycol monoacetate, diketone, and the like. Polyhydric alcohols such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether or monophenyl ether of propylene glycol or dipropylene glycol monoacetate and derivatives thereof; cyclic ethers such as dioxane; and methyl lactate; Ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate Can be exemplified Le, esters such as ethyl ethoxypropionate. These may be used alone or 2
You may mix and use more than one kind.

The method of using the chemically amplified negative resist composition of the present invention may be, for example, a conventional spinner coating method in which a coating solution prepared by dissolving in the above solvent is applied to a substrate such as a silicon wafer or a glass substrate. 0.
It is applied to a thickness of about 5 to 6.0 μm, dried to form a resist layer, and then exposed to ultraviolet light, deep UV,
After irradiating with an excimer laser beam or drawing and heating with an electron beam, the unexposed portion is selected by immersing in a developing solution, for example, an alkaline aqueous solution such as a 1 to 10% by weight aqueous solution of tetramethylammonium hydroxide. A method of forming a resist pattern by dissolving and removing the resist pattern. In particular, when a resist layer having a thickness not exceeding 3.0 μm is formed, the dissolution rate of the component (A) is 50 to 200.
It is preferable to use the component (A) alone at a rate of nm / s, preferably 80 to 100 nm / s. In a method called ion implantation, which implants ions such as phosphorus and boron into a silicon substrate or polysilicon. 3.0 to use as a mask
In order to form a relatively thick resist layer having a thickness of 6.0 μm, the component (A) is mixed with the component (A) as the component (A), and the dissolution rate is 50 to 300 nm / s, preferably 15 to 300 nm / s.
0 to 280 nm / s, more preferably 200 to 250
It is preferable to use one adjusted to be nm / s.

[0045]

Now, the present invention will be described in further detail with reference to Examples. However, it should be understood that the present invention is by no means restricted by such specific Examples.

Example 1 Weight average molecular weight 2500, molecular weight distribution (M _w / M _n )
13 poly p-hydroxystyrene (dissolution rate = 400
nm / s) 50 parts by weight, p-hydroxystyrene-styrene copolymer having a weight average molecular weight of 2500 and a molecular weight distribution ( _Mw / _Mn ) of 1.23 [p-hydroxystyrene: styrene = 85: 15 (molar ratio) , Dissolution rate = 98 nm / s]
50 parts by weight of an alkali-soluble resin component (dissolution rate = 230 nm / s), melamine resin Nicalac MW
15 parts by weight of -100 LM (manufactured by Sanwa Chemical Co., Ltd.) are dissolved in 180 parts by weight of propylene glycol monomethyl ether acetate, and α- (methylsulfonyloxyimino) -1-phenylacetonitrile 1 as an acid generator is added thereto.
5 parts by weight were dissolved to prepare a negative resist solution.

Next, the resist solution prepared above was applied on a silicon wafer using a spinner and dried on a hot plate at 110 ° C. for 90 seconds to form a resist layer having a thickness of 3.0 μm. This resist layer was reduced by using a reduction projection exposure apparatus NSR-2005i10D (manufactured by Nikon Corporation).
After selectively irradiating with i-rays, the mixture was heated at 110 ° C. for 90 seconds, and then developed with a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 65 seconds.
After washing with water for 0 second, it was dried. The sensitivity was 150 ms, and the resolution was 0.6 μm. The sensitivity was 1.0 μm after development.
1: 1 line and space resist pattern
Is a value expressed in milliseconds (ms), and the resolution is a value expressed by a limit resolution at an exposure amount for reproducing a mask pattern of 1.0 μm.

When the cross-sectional shape of the obtained 1.0 μm resist pattern was observed with a SEM (scanning electron microscope) photograph, it was a rectangular resist pattern perpendicular to the substrate. In addition, no undulating phenomenon was observed on the side surface, and the resist pattern was a good resist pattern in which the upper portion of the pattern was slightly rounded.

Example 2 In addition to the components of Example 1, 2,3,3 ', 4,4', 5 '
A resist layer having a thickness of 3.0 μm was formed on the substrate in the same manner as in Example 1 except that 3.0 parts by weight of hexahydroxybenzophenone was added and 180 parts by weight of propylene glycol monomethyl ether acetate was changed to 247 parts by weight.

When a resist pattern was formed on the resist layer in the same manner as in Example 1, the sensitivity was 280.
ms, and the resolution was 0.6 μm. 1.0μ obtained
Observation of the cross-sectional shape of the resist pattern m indicated that a rectangular resist pattern perpendicular to the substrate was obtained.
No waviness on the side was seen in the resist pattern,
The pattern had a good shape without roundness at the top of the pattern.

Example 3 Weight average molecular weight 2500, molecular weight distribution (M _w / M _n )
13 poly p-hydroxystyrene (dissolution rate = 400
p-hydroxystyrene-styrene copolymer having a weight-average molecular weight of 2,500 and a molecular weight distribution ( _Mw / _Mn ) of 1.23 [p-hydroxystyrene: styrene = 85: 15 (molar ratio) , Dissolution rate = 98 nm / s]
40 parts by weight of an alkali-soluble resin component (dissolution rate = 250 nm / s), melamine resin Nicalac MW
10 parts by weight of -100 LM (manufactured by Sanwa Chemical Co., Ltd.) are dissolved in 226 parts by weight of propylene glycol monomethyl ether acetate, and α- (methylsulfonyloxyimino) -1- (p-methoxyphenyl) as an acid generator is dissolved therein.
0.5 parts by weight of acetonitrile and chemical formula 24

[0052]

Embedded image 3.0 parts by weight of the compound represented by the formula was dissolved to prepare a negative resist solution.

A resist layer was formed on a substrate in the same manner as in Example 1 except that the thickness of the negative resist solution prepared above was changed to 4.0 μm. When a resist pattern was formed on this resist layer in the same manner as in Example 1, the sensitivity was 280 ms and the resolution was 0.6 μm. When the cross-sectional shape of the obtained 1.0 μm resist pattern was observed with a SEM photograph, it was a rectangular resist pattern perpendicular to the substrate. In addition, no undulating phenomenon was observed on the side surface, and the resist pattern was a good resist pattern in which the upper portion of the pattern was slightly rounded.

Example 4 In Example 1, 15 parts by weight of the acid generator α- (methylsulfonyloxyimino) -1-phenylacetonitrile was added to α- (methylsulfonyloxyimino) -1-
(P-methylphenyl) acetonitrile 15 parts by weight, α
1.2 μm in thickness in the same manner as in Example 1 except that 5 parts by weight of-(methylsulfonyloxyimino) -1- (p-methoxyphenyl) acetonitrile and 414 parts by weight of 247 parts by weight of propylene glycol monomethyl ether acetate were used. Was formed on the substrate.

When a resist pattern was formed on the above resist layer in the same manner as in Example 1, the sensitivity was 90 m
s, resolution was 0.4 μm. 1.0 μm obtained
When the cross-sectional shape of the resist pattern was observed, it was a rectangular resist pattern perpendicular to the substrate. In addition, no undulating phenomenon was observed on the side surface, and the resist pattern was a good resist pattern having no roundness at the top of the pattern.

Comparative Example 1 In Example 1, a p-hydroxystyrene-styrene copolymer having a weight average molecular weight of 2500 and a molecular weight distribution ( _Mw / _Mn ) of 1.23 [p-hydroxystyrene: styrene =
85:15 (molar ratio), dissolution rate = 98 nm / s] 50
Parts by weight are weight average molecular weight 2500, molecular weight distribution (M _w /
Example 1 except that 50 parts by weight of _Mn ) 1.13 poly-p-hydroxystyrene (dissolution rate = 400 nm / s) was used.
A resist pattern was formed in the same manner as described above. Sensitivity is 30
0 ms, and the resolution was 0.6 μm.

When the cross-sectional shape of the obtained 1.0 μm resist pattern was observed with a SEM photograph, a large number of microbridges were generated between the patterns, and the pattern had a shape in which the upper portion of the pattern was greatly reduced in film thickness. Was.

Comparative Example 2 A copolymer of p-hydroxystyrene-styrene having a weight average molecular weight of 5,000 and a molecular weight distribution ( _Mw / _Mn ) of 1.23 [p-hydroxystyrene: 100 parts by weight of both polymers in Example 1 was prepared. Styrene = 85: 15 (molar ratio), dissolution rate = 17 nm / s] A resist pattern was formed in the same manner as in Example 1 except that 100 parts by weight was used. Sensitivity is 200
ms, and the resolution was 0.75 μm.

When the cross-sectional shape of the obtained 1.0 μm resist pattern was observed with an SEM photograph, it was tapered and the contrast was extremely poor.

Example 5 Weight average molecular weight 2500, molecular weight distribution (M _w / M _n )
23 p-hydroxystyrene-styrene copolymer [p
-Hydroxystyrene: styrene = 85: 15 (molar ratio), dissolution rate = 98 nm / s], 100 parts by weight, melamine resin Nikalac MW-30 (manufactured by Sanwa Chemical Co., Ltd.) 1
5 parts by weight were dissolved in 617 parts by weight of propylene glycol monomethyl ether acetate, and 3.5 parts by weight of an acid generator α- (methylsulfonyloxyimino) -1-phenylacetonitrile was further added thereto, followed by 2,2 ′, 4 ,
2.0 parts by weight of 4'-tetrahydroxybenzophenone,
0.5 parts by weight of tripentylamine and 0.5 parts by weight of o-oxybenzoic acid were dissolved to prepare a negative resist solution.

The prepared resist solution was applied on a silicon wafer using a spinner and dried on a hot plate at 100 ° C. for 90 seconds to form a 0.8 μm-thick resist layer. A reduction projection exposure apparatus N
After selectively irradiating i-line using SR-2005i10D (manufactured by Nikon Corporation), heating at 120 ° C. for 90 seconds, and then developing with a 2.38 wt% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 65 seconds. After washing with water for 30 seconds and drying. Sensitivity 200ms, resolution 0.32
μm. The sensitivity is an exposure time in which a 0.5 μm line-and-space resist pattern is formed at a ratio of 1: 1 after development. The value is expressed in milliseconds (ms). The resolution is 0.5 μm. This is a value represented by a limit resolution at an exposure amount for reproducing a mask pattern.

When the cross-sectional shape of the obtained 0.5 μm resist pattern was observed by an SEM photograph, it was a rectangular resist pattern perpendicular to the substrate. Neither the tapering phenomenon on the upper part of the pattern nor the waving phenomenon on the side surface occurred, and the resist pattern was excellent in shape.

Comparative Example 3 A p-hydroxystyrene-styrene copolymer having a weight average molecular weight of 2500 and a molecular weight distribution (M _w / M _n ) of 1.23 in Example 5 [p-hydroxystyrene: styrene = 8
5:15 (molar ratio), dissolution rate = 98 nm / s], weight average molecular weight 3500, molecular weight distribution (M _w / M _n ) 2.10
Of poly p-hydroxystyrene (dissolution rate = 400 nm)
/ S), a resist pattern was formed in the same manner as in Example 5 except that the resist pattern was changed to / s). The sensitivity is 420 ms and the resolution is 0.40
μm.

When the cross-sectional shape of the obtained 0.5 μm resist pattern was observed with a SEM photograph, the upper portion of the pattern was largely reduced in film thickness and rounded, and the lower portion of the pattern was a pattern with a skirt.

Comparative Example 4 A p-hydroxystyrene-styrene copolymer having a weight average molecular weight of 2500 and a molecular weight distribution (M _w / M _n ) of 1.23 in Example 5 [p-hydroxystyrene: styrene = 8
5:15 (molar ratio), dissolution rate = 98 nm / s], weight average molecular weight 1500, molecular weight distribution (M _w / M _n ) 1.26
P-hydroxystyrene-styrene copolymer (p-hydroxystyrene: styrene = 70: 30 (molar ratio),
A resist pattern was formed in the same manner as in Example 5, except that the dissolution rate was changed to 40 nm / s). Sensitivity is 240m
s, Resolution was 0.50 μm.

When the cross-sectional shape of the obtained 0.5 μm resist pattern was observed with an SEM photograph, residual development occurred between the patterns, and the contrast was extremely poor.

Comparative Example 5 A p-hydroxystyrene-styrene copolymer having a weight average molecular weight of 2500 and a molecular weight distribution ( _Mw / _Mn ) of 1.23 in Example 5 [p-hydroxystyrene: styrene = 8
5:15 (molar ratio), dissolution rate = 98 nm / s]) with a weight average molecular weight of 5000 and a molecular weight distribution ( _Mw / _Mn ) of 1.2.
3 p-hydroxystyrene-styrene copolymer [p-
A resist pattern was formed in the same manner as in Example 5, except that hydroxystyrene: styrene = 85: 15 (molar ratio), dissolution rate = 17 nm / sec]. The sensitivity was 180 ms and the resolution was 0.45 μm.

When the cross-sectional shape of the obtained 0.5 μm resist pattern was observed with an SEM photograph, residual development occurred between the patterns, and the cost was extremely poor.

Example 6 Weight average molecular weight 2500, molecular weight distribution (M _w / M _n )
21 p-hydroxystyrene-styrene copolymer [p
-Hydroxystyrene: styrene = 85: 15 (molar ratio), dissolution rate = 87 nm / s], 100 parts by weight, and 9 parts by weight of urea resin Nikalac MX-290 (manufactured by Sanwa Chemical Co.) are dissolved in 622 parts by weight of ethyl lactate. Then, 9 parts by weight of tris (2,3-dibromopropyl) isocyanurate was added as an acid generator, and the mixture was stirred well to prepare a negative resist solution.

Next, the resist solution was applied on a silicon wafer using a spinner and dried on a hot plate at 100 ° C. for 90 seconds to form a resist layer having a thickness of 0.7 μm. A reduction projection exposure apparatus N
After selectively excimer laser irradiation using SR-2005EX8A (manufactured by Nikon Corporation), the excimer laser was heated at 120 ° C. for 90 seconds, and then developed with a 2.38 wt% aqueous solution of tetramethylammonium hydroxide at 23 ° C. for 65 seconds. After washing with water for 30 seconds and drying. Sensitivity is 80mJ / c
m ² , and the resolution was 0.26 μm. The sensitivity is
The exposure amount is such that a 0.3 μm line-and-space resist pattern is formed at a ratio of 1: 1 after development, and mJ / cm
^The resolution is represented by ^two units, and the resolution is a value represented by a limit resolution at an exposure amount for reproducing a 0.3 μm mask pattern.

When the cross-sectional shape of the obtained 0.30 μm resist pattern was observed with a SEM photograph, it was found that the pattern top had no roundness and was a good rectangular resist pattern perpendicular to the substrate.

[0072]

Industrial Applicability The chemically amplified negative resist composition of the present invention has high sensitivity, high resolution, excellent heat resistance,
It is a negative resist composition capable of forming a resist pattern having an excellent profile shape. By using the chemically amplified negative resist composition of the present invention, a thick-film resist pattern can be easily formed, and a resist pattern having a thickness of 3.0 to 6.0 μm can be obtained by mixing the component (a) with the component (b). By selectively irradiating the active light of 300 to 500 nm with the component (A) composed of the mixture, a good profile shape can be formed.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03F 7/004 503 G03F 7/004 503Z 7/033 7/033 7/30 7/30 H01L 21/027 H01L 21/30 502R 569F (72) Inventor Yoshiki Sugata 150 Nakamaruko, Nakahara-ku, Kawasaki City, Kanagawa Prefecture Inside Tokyo Keika Kogyo Co., Ltd.

Claims (18)

[Claims] 1. A chemically amplified negative resist composition comprising (A) an alkali-soluble resin, (B) a compound which generates an acid upon irradiation with radiation, and (C) a compound which undergoes a crosslinking reaction in the presence of an acid. Wherein the component (A) is (A)
At least hydroxystyrene constituent unit, the weight average molecular weight (M _W) is 2000 to 4000, a weight average molecular weight to number average molecular weight (M _N) and a ratio of (M _W / M _N) is 1.0
Or a copolymer in the range of from 2.0 to 2.0,
2.3. At 23 ° C. of the component (A) consisting of a mixture of the component and (b) hydroxystyrene homopolymer.
A chemically amplified negative resist composition having a dissolution rate in an aqueous solution of 8% by weight of tetramethylammonium hydroxide in the range of 50 to 300 nm / s. 2. The chemical amplification method according to claim 1, wherein the monomer forming the structural unit other than the hydroxystyrene structural unit of the component (a) is a monomer obtained by substituting the hydroxyl group of hydroxystyrene with another group. Negative resist composition. 3. The chemical amplification type according to claim 1, wherein the monomer forming the structural unit other than the hydroxystyrene structural unit of the component (a) is a monomer having an α, β-unsaturated double bond. Negative resist composition. 4. The chemically amplified negative resist composition according to claim 3, wherein the monomer having an α, β-unsaturated double bond is styrene. 5. The hydroxystyrene structural unit of the component (a) and the structural unit other than the structural unit in a molar ratio of 80:20 to
5. The chemically amplified negative resist composition according to claim 1, wherein the composition is 90:10. 6. The method according to claim 1, wherein the dissolution rate of the component (a) in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide at 23 ° C. is 50 to 200 nm / s. Item 7. The chemically amplified negative resist composition according to Item 1. 7. (b) component of the M _W is 2000 to 4000,
M _W / M _N is a chemically amplified negative resist composition according to claim 1, characterized in that 1.0 to 2.0. 8. The chemically amplified negative type according to claim 1, wherein the component (A) is a mixture of the components (a) and (b) in a weight ratio of 1: 2 to 2: 1. Resist composition. 9. A mixture of component (a) and component (b) at 23 ° C.
Dissolution rate in 2.38 wt% tetramethylammonium hydroxide aqueous solution at 150 to 280 n
9. The chemically amplified negative resist composition according to claim 8, wherein the composition is m / s. 10. A compound represented by the general formula 1 as a component (B): (Wherein, R ¹ represents a monovalent to trivalent organic group, R ² represents a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic compound group, and n represents 1 to 3 2. The chemically amplified negative resist composition according to claim 1, comprising a compound represented by the formula (1) or a mixture thereof. (11) The component (B) has the general formula (2): (In the formula, R ³ and R ⁴ each represent a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic compound group, and R ³ and R ⁴ are simultaneously an aromatic compound group. 11. The chemically amplified negative resist composition according to claim 10, which is a compound represented by the following formula: The component (B) is represented by the general formula 3 (Wherein, R ⁵ represents a divalent organic group, and R ⁶ represents a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic compound group). The chemically amplified negative resist composition according to claim 10, wherein (13) The component (B) has the general formula 4 (In the formula, R ⁷ and R ⁸ each represent a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic compound group, and R ⁷ and R ⁸ are simultaneously an aromatic compound group. And the compound represented by the general formula 5 (Wherein R ⁹ represents a divalent organic group, and R ¹⁰ represents a substituted or unsubstituted saturated hydrocarbon group, unsaturated hydrocarbon group or aromatic compound group). The chemically amplified negative resist composition according to claim 10, wherein: 14. The component (B) is composed of α- (methylsulfonyloxyimino) -1- (p-methoxyphenyl) acetonitrile and a compound represented by the following chemical formula (6). The chemically amplified negative resist composition according to claim 13, comprising a mixture with a compound represented by the formula: (15) The component (B) has the general formula (7). 2. A chemically amplified negative according to claim 1, which contains a compound represented by the formula: wherein R ^{11 to} R ¹³ may be the same or different and each represents a halogenated alkyl group. -Type resist composition. 16. A coating solution of the chemical amplification type negative resist composition according to claim 1, which is applied on a substrate, and thereafter, 200 to 5 times.
A method for forming a negative resist pattern, comprising selectively irradiating with an actinic ray of 00 nm and then developing with an aqueous alkali solution. 17. The method according to claim 1, wherein the component (A) is the component (A).
After coating and drying the coating solution of the chemically amplified negative resist composition described on the substrate, a resist layer having a film thickness not exceeding 3.0 μm is formed, and then selectively irradiated with actinic rays of 200 to 500 nm. And developing with an aqueous alkali solution. 18. A coating solution of the chemically amplified negative resist composition according to claim 1, wherein the component (A) is a mixture of the component (a) and the component (b), followed by drying on a substrate. 3.0
To form a resist layer having a thickness of about 6.0 μm;
A method for forming a negative resist pattern, comprising selectively irradiating an actinic ray of 0 to 500 nm and developing with an aqueous alkali solution.